How to Add a Custom Text Field in Shopify Checkout

Are you looking to enhance your Shopify checkout process by adding a custom text input field? Whether you need to collect additional information from your customers or streamline your order processing, this guide will walk you through the process of adding a custom field to the “Information” step of your Shopify checkout.

Understanding the Need for Custom Fields

Why Add Custom Fields?

Custom fields in the checkout process can serve various purposes:

1. Collecting essential order information
2. Improving order processing efficiency
3. Enhancing customer experience

Common Use Cases

Some common scenarios where custom fields are beneficial include:

1. Capturing purchase order numbers for B2B transactions
2. Requesting special delivery instructions
3. Collecting additional customer preferences

Adding a Custom Text Input Field to Shopify Checkout

Prerequisites

Before we dive into the implementation, ensure you have:

1. Access to your Shopify store’s theme files
2. Basic knowledge of HTML, CSS, and JavaScript
3. Shopify Plus account (for full checkout customization)

Step-by-Step Implementation

1. Accessing the Checkout.liquid File

To add a custom field to the checkout, you’ll need to edit the checkout.liquid file. This file is typically only available to Shopify Plus merchants. If you’re on a Plus plan and don’t see this file, contact Shopify support to have it enabled for your store.

2. Creating a Custom JavaScript File

Create a new JavaScript file in your theme’s assets folder. Let’s call it custom-checkout.js. This file will contain the code to add and manage your custom field.

3. Writing the Custom Field Code

In your custom-checkout.js file, add the following code:

$(document).on(`page:load page:change`, function() {
  if (Shopify.Checkout.step == 'contact_information'){
    var input = '<div class="section section--purchase-order">' +
                  '<div class="section__header">' +
                    '<h2 class="section__title">Purchase Order Number</h2>' +
                  '</div>' +
                  '<div class="section__content">' +
                    '<div class="fieldset">' +
                      '<div class="field__input-wrapper">' +
                        '<label class="field__label field__label--visible" for="checkout_purchase_order_number">Purchase Order Number</label>' +
                        '<input placeholder="Purchase Order Number" autocorrect="off" class="field__input" aria-required="true" size="30" type="text" value="" name="checkout[attributes][purchaseOrderNumber]" id="checkout_purchase_order_number">' +
                      '</div>' +
                    '</div>' +
                  '</div>' +
                '</div>';
    
    $(".section--contact-information:first").after(input);
    
    $("#checkout_purchase_order_number").change(function(){
      var obj = $("#checkout_purchase_order_number").val();
      sessionStorage.setItem("purchase_order_number", obj);
    });
    
    var savedObj = sessionStorage.getItem("purchase_order_number");
    if (savedObj !== null) {
      $("#checkout_purchase_order_number").val(savedObj);
    }
  }
});

This code creates a new input field for the Purchase Order Number, adds it to the checkout page, and manages its state using session storage.

4. Including the Custom JavaScript in Checkout

To include your custom JavaScript file in the checkout process, add the following line to your checkout.liquid file, just before the closing “ tag:

{{ 'custom-checkout.js' | asset_url | script_tag }}

5. Adding jQuery to Checkout

If you’re using jQuery in your custom code (as in the example above), make sure it’s included in your checkout. Add this line to the `section of yourcheckout.liquid` file:

{{ 'jquery-3.6.0.min.js' | asset_url | script_tag }}

Replace jquery-3.6.0.min.js with the appropriate version of jQuery you’re using.

Testing and Troubleshooting

After implementing these changes:

1. Test your checkout process thoroughly
2. Ensure the custom field appears correctly
3. Verify that the entered data is being saved and processed correctly

If you encounter any issues, double-check your code and make sure all files are properly linked.

Best Practices for Custom Checkout Fields

Keeping It Simple

When adding custom fields to your checkout:

1. Only ask for essential information
2. Keep the field labels clear and concise
3. Use placeholder text to guide users

Maintaining Consistency

To provide a seamless checkout experience:

1. Match the styling of your custom field to Shopify’s default fields
2. Ensure the field placement makes logical sense in the checkout flow
3. Use consistent terminology across your store and checkout process

Optimizing for Mobile

With increasing mobile commerce, it’s crucial to:

1. Test your custom fields on various mobile devices
2. Ensure the fields are easily tappable on smaller screens
3. Consider using appropriate input types (e.g., number for numeric inputs)

By following these guidelines and implementing the provided code, you can successfully add a custom text input field to your Shopify checkout’s information step. This enhancement can significantly improve your order processing and provide a better experience for your customers.